The Castro Valley Sanitary District owns a 25% interest in the WWTP. CVSan maintains its collection system independently. Oro Loma Sanitary District receives the CVSan flow at a point roughly 1.5 miles upstream of the WWTP.
Population served: 145,085
The Oro Loma Sanitary District was formed in 1811 and remained relatively rural until experiencing significant residential growth following the end of World War 2.
COLLECTION SYSTEM
“More than half of the collection system was already in place before the introduction of improved VCP manufacturing standards, which began in the mid- l950s. Notwithstanding this, video inspection indicates that the overall condition of the District’s Collection System is very good.”
A Unique Situation: The Hayward Fault crosses through the District. The District has identified all fault crossings and plotted the locations of each sewer line crossing. There are a total of 14 fault/sewer crossings ranging in size from 6 to 24 inches. The District has also identified and documented critical assets, including freeway crossings, lines in special easements, and unique structures, which are critical to the overall operation of the collection system.
After an earthquake, the ability to quickly assess the condition of the Collection System is vital. The District has pre-selected 28 structures that, upon inspection, will identify line failures. The 28 locations are broken down and prioritized into three lists of ten sites, labeled A, B, and C. Each sheet contains directions to the structure, as well as what normal flow conditions should look like. Directions start at the Plant to each structure location. This system is designed so that, in an emergency, the task can be assigned to any District employee who is physically able to open a maintenance hole cover.
“The District has had an active Sewer System Management Program since 1988, and has experienced very few line stoppages in recent years. Overflows are even less frequent. Stoppages and spills have been on a steady decline since 1992, when the District focused its efforts on aggressive line cleaning, continuous video inspection, and dedicated funding to repair or replace every line defect which could result in a service interruption.”
CWEA is now accepting nominations for the 2026–27 Awards Program. If your collection system demonstrates excellence in operations, maintenance, innovation, safety, and service to its community, we encourage you to apply.
Collection System of the Year awards are presented in small, medium, and large categories. All nominees must be CWEA members and advance through their Local Section before completing the statewide application.
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